Alastair Cook put the eight-wicket defeat suffered in the fourth Ashes Test in Melbourne down to a lack of confidence.

Midway through the third day of the Boxing Day Test the tourists looked to be in control of the match, reaching 64 without loss after claiming a first-innings lead of 51 runs.

Fast forward just over 24 hours and Australia had cruised to a victory target of 231, opener Chris Rogers leading their run chase with 116 while Shane Watson weighed in with an unbeaten 83.

Cook was left to lament yet another batting collapse by England; at one stage they lost three wickets for one run in six balls, before then seeing their last five go down for six runs in a dramatic evening session.

"It's a tough time, when you're losing games of cricket," the opener - who passed 8,000 Test runs at Melbourne - said.

"In this game we got ourselves an opportunity to win it. Certainly yesterday afternoon with the bat, 60 for nought and building a nice lead... It probably shows where we're at at the moment as a side, and the levels of confidence.

"When you're winning games of cricket you can dominate those positions. When you're struggling for a bit of confidence, you can let those positions slip, and that's what we've done in this game."

Missed chances

Cook was at a loss to explain why things were going so badly wrong for England, who now travel to Sydney in danger of suffering a series whitewash.

They did not help themselves with two missed chances in the field on the fourth morning, the skipper himself putting down a tough opportunity off Rogers when he had 19 and then shelled David Warner at first slip soon after.

"The first half an hour, we created three chances," Cook said. "When it's a low run-chase, you need to take those chances. We didn't take them and we got punished.

"There's a lot of things I struggle to explain. We're working as hard as we can at our game. That's the only thing we can do in these situations - keep it as simple as you can in your mind, work at every single aspect, desperately trying to improve.

"We know that will bear fruit at some stage in the future. It's not quite happening at the moment. We've got one more chance to change that."

The match in Melbourne was the first for England since the sudden retirement of Graeme Swann, though Cook refused to use the spinner's absence as a reason for yet another defeat.

"You can't use that as an excuse," he said. "That would be taking the easy way out. We've got to just keep working as hard as we can at our game and it will turn eventually - hopefully it will turn next week (in the fifth Test in Sydney).

"We got ourselves in the position to win this game. We didn't do it. Obviously, when you get yourselves in the position, it hurts more. We've got to dust ourselves off.

"The support makes us privileged to wear the shirt. We're not quite doing it justice at the moment, but, just to let everyone know, we're trying as hard as we can."